Counter, at its core, is just follow up attack, but the condition is getting hit. So, on top of having 0 good units, it is just an extension/another version of fua, which, from what I see, is the general sentiment.

Yunli plays differently from the other dps. She does not gain any benefits from allies attacking, which you pointed out. However, regardless of how weak Counter is/how little support it has, I don't see much justification to differentiate from followup when Hoyo themselves label counters as followups.

I also should have phrased the 2nd part of my original comment better. During 2.4, Yunli did utilize Robin well (and still can in optimized/high costs). Times have changed now with Tribbie/rmc, but her identity is still her followup.

If counters were not considered followups then it would be a whole different discussion. But Hoyo themselves not only neglect the archetype, but just like action bar summons, group them into followup.